SINGAPORE — Svetlana Kuznetsova became the first player to reach the last four of the WTA Finals after sealing her second round-robin victory this week, beating Karolina Pliskova on Wednesday.

Kuznetsova fell to the ground, smiling, after securing a 3-6, 6-2, 7-6 (6) win on a fourth match point.

"I felt the support of the crowd and I couldn't let anyone down," said Kuznetsova, who at 22-8 has the most three-set match wins this year. "So I had to fight."

When defending champion Agnieszka Radwanska prevailed over Garbine Muguruza 7-6 (1), 6-3 in the second match, the Pole's win guaranteed Kuznetsova's progress in the competition.

In five previous WTA Finals appearances, Kuznetsova had never advanced beyond the round-robin stage.

Muguruza's 0-2 standing eliminates the Spaniard from semifinal contention. The second semifinal berth in the White Group will be decided between Radwanska (1-1) and Pliskova (1-1) on Friday.

The four players from the Red Group - No. 1 Angelique Kerber (2-0), Simona Halep (1-1), Madison Keys (1-1) and Dominika Cibulkova (0-2) - will vie for the two semifinal spots in round-robin matches on Thursday.

Kuznetsova served for the match at 5-3, but never had a match point until the tiebreaker. Pliskova had an opportunity to serve out the match at 6-5.

Kuznetsova returned to a top 10 ranking this year for the first time since she last played at the WTA Finals in 2009.

When the two-time Grand Slam champion was asked what's helped her recapture her flair for the game, she said, "My heart. I just love (it). I've not been at my best my past years. Something changed this year and I'm just enjoying my game."

Kuznetsova travelled to Singapore after securing the last berth in the year-end competition by winning the Moscow title last Saturday.

On Monday, a fatigued Kuznetsova saved a match point to capture a dramatic three-set win over Radwanska. During the match, Kuznetsova chopped off a portion of her hair braid that was flapping in her face.

Kuznetsova suggested if a movie was to be made of her last week it should be titled either "Life of a Hustler" or "Workaholic."